As is well known by anyone who has owned or driven a vehicle with a diesel engine, whether it be auto, pick-up or large eighteen wheeler, cold weather reduces the viscosity of diesel fuel. Since all diesel engines, regardless of size, are of the injected fuel type, cold weather automatically produces injector problems resulting from the reduced temperature of the diesel fuel.
Some of the problems which occur in diesel engines at reduced temperatures are fuel clouding, waxing and ice formation in the fuel lines, fittings and injectors. Waxing usually results in sticking injectors which will significantly reduce the performance efficiency of the engine. The effects of water or moisture droplets freezing in a fuel line can have an even more drastic effect on engine performance. If the concentration of water or moisture in the diesel fuel is sufficiently high, it will result in these droplets freezing and thus blocking the fuel lines, bringing the engine to a halt.
In view of the above known facts, there has been a considerable amount of research and development directed at this serious problem. For example, separators have been utilized to absorb moisture in the fuel lines and thus reduce the possibility of icing in the fuel lines. In addition, a variety of fuel heaters have been developed. However, none of the known fuel heating systems have been able to bring about an acceptable solution to the above noted problem. A known heating system utilized a heat exchange tube in the fuel tank with the heat exchange tube being connected to the engine's cooling system. After a period of time, such systems have been known to develop a fracture of the heat exchange tube in the fuel tank, thus contaminating the diesel tank with a mixture of water and antifreeze.
Another known system uses an in-line heat exchanger after the diesel fuel has left the tank and is on its way to the injector manifold. The problem with this type of system was the fact that the heat exchanger only heated the diesel fuel after it left the tank. Thus any water or moisture droplets which are in the tank or tanks can freeze resulting in blockage of the lines.